Abstract: A third aldehyde or ketone is added to a binary mixture of aldehyde and/or ketones used in preparing mixtures of pyridine and alkyl-substituted pyridines in large scale continuous processes. The amount of the third component is appropriately adjusted whereby the relative ratio(s) of products are adjusted and the total yield of pyridines and/or alkyl-substituted pyridines is high, all without any plant shut-down. In a preferred system, propionaldehyde is added to a binary mixture of acetaldehyde and formaldehyde to produce surprisingly high amounts of beta-pyridine and pyridine.

Abstract: A method of preparing UV-grade synthetic pyridine from a pyridine-containing reaction product mixture which also contains at least one other compound which is UV absorbing to a sufficient extent that said pyridine mixture is not UV grade, said mixture being obtained from the condensation reaction, over an effective catalyst, of one of more aldehydes and/or ketones with one or more amines and/or ammonia, comprises recovering from said mixture a pyridine-water azeotrope effective to separate pyridine therefrom sufficiently free of UV-absorbing compounds to be UV grade.

Abstract: A process for preparing pyridine or alkyl substituted pyridines in high yield, comprises reacting a C.sub.2-5 -aldehyde, a C.sub.3-5 -ketone or a mixture thereof, ammonia and, optionally, formaldehyde, in the gas phase in contact with a fluidized or otherwise movable bed of a catalytically effective amount of a crystalline aluminosilicate zeolite catalyst in the acidic form and having a constraint index of about 1 to about 12, with an actual contact time of the reactants with the catalyst which is at least as great as said actual contact time when the reaction is conducted in a 1 inch diameter fluid bed reactor with a pseudo contact time of at least about 2.5 seconds.